Tested on i7-12700k machine with gcc 11.3.0 with GentooLTO overlay. When both CFLAGS are enabled, the compilation takes forever (>1hr) with very low CPU utilization. Building with MAKEOPTS="-j1" reveals that the build stuck on compiling `src/language.cpp`, which is a file with huge numbers of included headers. Removing either of the flags would allow a swift build. (<1min) Unfortunately both flags are enabled by default in GentooLTO project. I'm not sure whether this should be classified as a compiler bug, a GentooLTO problem or a package-level CFLAG filter. emerge --info ``` Portage 3.0.38.1 (python 3.11.0-final-0, default/linux/amd64/17.1/desktop/gnome/systemd, gcc-11.3.0, glibc-2.36-r5, 5.15.74.2-microsoft-standard-WSL2 x86_64) ================================================================= System uname: Linux-5.15.74.2-microsoft-standard-WSL2-x86_64-12th_Gen_Intel-R-_Core-TM-_i7-12700K-with-glibc2.36 KiB Mem: 61720864 total, 55723664 free KiB Swap: 0 total, 0 free Timestamp of repository gentoo: Thu, 17 Nov 2022 17:00:01 +0000 Head commit of repository gentoo: b30c6342fd147e7b3629241ca168db29f7c5b825 Timestamp of repository lto-overlay: Thu, 10 Nov 2022 17:16:47 +0000 Head commit of repository lto-overlay: a3ac13deb3c2022dfc49c64d3e13c7a06655d95a Timestamp of repository mv: Sat, 12 Nov 2022 19:46:46 +0000 Head commit of repository mv: 0af5ec83a504adf0dfe61bec7aca68b00e8546ed sh bash 5.1_p16-r2 ld GNU ld (Gentoo 2.38 p4) 2.38 ccache version 4.5.1 [disabled] app-misc/pax-utils: 1.3.5::gentoo app-shells/bash: 5.1_p16-r2::gentoo dev-lang/perl: 5.34.1-r4::gentoo dev-lang/python: 2.7.18_p16::gentoo, 3.8.15_p3::gentoo, 3.10.8_p3::gentoo, 3.11.0_p2::gentoo dev-lang/rust: 1.65.0::gentoo dev-util/ccache: 4.5.1::gentoo dev-util/cmake: 3.24.2::gentoo dev-util/meson: 0.63.2-r1::gentoo sys-apps/baselayout: 2.9::gentoo sys-apps/sandbox: 2.29::gentoo sys-apps/systemd: 251.4::gentoo sys-devel/autoconf: 2.13-r2::gentoo, 2.71-r1::gentoo sys-devel/automake: 1.16.5::gentoo sys-devel/binutils: 2.38-r2::gentoo sys-devel/binutils-config: 5.4.1::gentoo sys-devel/clang: 14.0.6-r1::gentoo, 15.0.3::gentoo sys-devel/gcc: 11.3.0::gentoo sys-devel/gcc-config: 2.8::gentoo sys-devel/libtool: 2.4.7::gentoo sys-devel/llvm: 14.0.6-r2::gentoo, 15.0.3::gentoo sys-devel/make: 4.3::gentoo sys-kernel/linux-headers: 5.15-r3::gentoo (virtual/os-headers) sys-libs/glibc: 2.36-r5::gentoo Repositories: gentoo location: /var/db/repos/gentoo sync-type: rsync sync-uri: rsync://rsync.gentoo.org/gentoo-portage priority: -1000 sync-rsync-extra-opts: sync-rsync-verify-jobs: 1 sync-rsync-verify-max-age: 24 sync-rsync-verify-metamanifest: yes local location: /var/db/repos/local masters: gentoo lto-overlay location: /var/db/repos/lto-overlay sync-type: git sync-uri: https://github.com/gentoo-mirror/lto-overlay.git masters: gentoo mv mv location: /var/db/repos/mv sync-type: git sync-uri: https://github.com/gentoo-mirror/mv.git masters: gentoo ACCEPT_KEYWORDS="amd64" ACCEPT_LICENSE="@FREE" CBUILD="x86_64-pc-linux-gnu" CFLAGS="-march=native -O3 -fgraphite-identity -floop-nest-optimize -fipa-pta -fno-semantic-interposition -flto=16 -fuse-linker-plugin -pipe" CHOST="x86_64-pc-linux-gnu" CONFIG_PROTECT="/etc /usr/share/gnupg/qualified.txt" CONFIG_PROTECT_MASK="/etc/ca-certificates.conf /etc/dconf /etc/env.d /etc/fonts/fonts.conf /etc/gconf /etc/gentoo-release /etc/revdep-rebuild /etc/sandbox.d /etc/terminfo" CXXFLAGS="-march=native -O3 -fgraphite-identity -floop-nest-optimize -fipa-pta -fno-semantic-interposition -flto=16 -fuse-linker-plugin -pipe" DISTDIR="/var/cache/distfiles" ENV_UNSET="CARGO_HOME DBUS_SESSION_BUS_ADDRESS DISPLAY GOBIN GOPATH PERL5LIB PERL5OPT PERLPREFIX PERL_CORE PERL_MB_OPT PERL_MM_OPT XAUTHORITY XDG_CACHE_HOME XDG_CONFIG_HOME XDG_DATA_HOME XDG_RUNTIME_DIR XDG_STATE_HOME" FCFLAGS="-march=native -O3 -pipe" FEATURES="assume-digests binpkg-docompress binpkg-dostrip binpkg-logs binpkg-multi-instance buildpkg-live config-protect-if-modified distlocks ebuild-locks fixlafiles ipc-sandbox merge-sync multilib-strict network-sandbox news parallel-fetch pid-sandbox preserve-libs protect-owned qa-unresolved-soname-deps sandbox sfperms strict unknown-features-warn unmerge-logs unmerge-orphans userfetch userpriv usersandbox usersync xattr" FFLAGS="-march=native -O3 -pipe" GENTOO_MIRRORS="http://distfiles.gentoo.org" LANG="C.UTF8" LDFLAGS="-Wl,-O1 -Wl,--as-needed" MAKEOPTS="-j16" PKGDIR="/var/cache/binpkgs" PORTAGE_CONFIGROOT="/" PORTAGE_RSYNC_OPTS="--recursive --links --safe-links --perms --times --omit-dir-times --compress --force --whole-file --delete --stats --human-readable --timeout=180 --exclude=/distfiles --exclude=/local --exclude=/packages --exclude=/.git" PORTAGE_TMPDIR="/var/tmp" RUSTFLAGS="-C target-cpu=native" SHELL="/bin/bash" USE="X a52 aac acl acpi alsa amd64 bluetooth branding bzip2 cairo cdda cdr cli colord crypt cups dbus dri dts dvd dvdr eds encode eselect-ldso evo exif ffmpeg flac fortran gdbm gif gnome gnome-keyring gnome-online-accounts gpm gstreamer gtk gui iconv icu introspection ipv6 jpeg lcms libglvnd libnotify libsecret libtirpc mad mng mp3 mp4 mpeg multilib nautilus ncurses networkmanager nls nptl ogg opengl openmp pam pango pcre pdf png policykit ppds pulseaudio qt5 readline sdl seccomp spell split-usr ssl startup-notification svg sysprof systemd test-rust tiff tracker truetype udev udisks unicode upower usb vorbis wayland wxwidgets x264 xattr xcb xml xv xvid zlib" ABI_X86="64" ADA_TARGET="gnat_2021" APACHE2_MODULES="authn_core authz_core socache_shmcb unixd actions alias auth_basic authn_alias authn_anon authn_dbm authn_default authn_file authz_dbm authz_default authz_groupfile authz_host authz_owner authz_user autoindex cache cgi cgid dav dav_fs dav_lock deflate dir disk_cache env expires ext_filter file_cache filter headers include info log_config logio mem_cache mime mime_magic negotiation rewrite setenvif speling status unique_id userdir usertrack vhost_alias" CALLIGRA_FEATURES="karbon sheets words" COLLECTD_PLUGINS="df interface irq load memory rrdtool swap syslog" CPU_FLAGS_X86="aes avx avx2 avx512f avx512dq avx512cd avx512bw avx512vl avx512vbmi f16c fma3 mmx mmxext pclmul popcnt rdrand sha sse sse2 sse3 sse4_1 sse4_2 ssse3" ELIBC="glibc" GPSD_PROTOCOLS="ashtech aivdm earthmate evermore fv18 garmin garmintxt gpsclock greis isync itrax mtk3301 nmea ntrip navcom oceanserver oldstyle oncore rtcm104v2 rtcm104v3 sirf skytraq superstar2 timing tsip tripmate tnt ublox ubx" INPUT_DEVICES="libinput" KERNEL="linux" LCD_DEVICES="bayrad cfontz cfontz633 glk hd44780 lb216 lcdm001 mtxorb ncurses text" LIBREOFFICE_EXTENSIONS="presenter-console presenter-minimizer" LUA_SINGLE_TARGET="lua5-1" LUA_TARGETS="lua5-1" OFFICE_IMPLEMENTATION="libreoffice" PHP_TARGETS="php7-4 php8-0" POSTGRES_TARGETS="postgres12 postgres13" PYTHON_SINGLE_TARGET="python3_10" PYTHON_TARGETS="python3_10 python3_11" RUBY_TARGETS="ruby27" USERLAND="GNU" VIDEO_CARDS="amdgpu fbdev intel nouveau radeon radeonsi vesa d3d12 dummy v4l" XTABLES_ADDONS="quota2 psd pknock lscan length2 ipv4options ipset ipp2p iface geoip fuzzy condition tee tarpit sysrq proto steal rawnat logmark ipmark dhcpmac delude chaos account" Unset: ADDR2LINE, AR, ARFLAGS, AS, ASFLAGS, CC, CCLD, CONFIG_SHELL, CPP, CPPFLAGS, CTARGET, CXX, CXXFILT, ELFEDIT, EMERGE_DEFAULT_OPTS, EXTRA_ECONF, F77FLAGS, FC, GCOV, GPROF, INSTALL_MASK, LC_ALL, LD, LEX, LFLAGS, LIBTOOL, LINGUAS, MAKE, MAKEFLAGS, NM, OBJCOPY, OBJDUMP, PORTAGE_BINHOST, PORTAGE_BUNZIP2_COMMAND, PORTAGE_COMPRESS, PORTAGE_COMPRESS_FLAGS, PORTAGE_RSYNC_EXTRA_OPTS, RANLIB, READELF, SIZE, STRINGS, STRIP, YACC, YFLAGS ```
CORRECTION: The actual CFLAGS used by GentooLTO should be part of emerge --info ``` CFLAGS="-march=native -O3 -fgraphite-identity -floop-nest-optimize -fdevirtualize-at-ltrans -fipa-pta -fno-semantic-interposition -flto=16 -fuse-linker-plugin -pipe" ```
I think will need to report this upstream to GCC if you can give a single command which triggers it, then ideally give a preprocessed source too. Similar to https://wiki.gentoo.org/wiki/Gcc-ICE-reporting-guide. Please link the bug here if/when you do. Thank you!
(In reply to Sam James from comment #2) > I think will need to report this upstream to GCC if you can give a single > command which triggers it, then ideally give a preprocessed source too. > > Similar to https://wiki.gentoo.org/wiki/Gcc-ICE-reporting-guide. > > Please link the bug here if/when you do. Thank you! I tried to reproduce w/ gcc 13 and couldn't, too.
